What Ratio of Vinegar and Baking Soda Produces the Highest

Felisa Zen
Aim

To find out what mass of baking soda
reacted with 10mL of vinegar will
produce the greatest volume of carbon
dioxide in a 100mL eudiometer tube
Background information

Baking soda is a base scientifically
known as sodium bicarbonate
 NaHCO3

Vinegar is dilute acetic acid
 CH3COOH

When sodium bicarbonate and acetic
acid are reacted, they produce a double
displacement acid-base reaction
Chemical Equation
NaHCO3(aq) + CH3COOH(aq)  NaCH3COO(aq) + H2CO3(aq)



NaCH3COO is a salt known as sodium acetate
H2CO3 is an unstable carbonic acid which quickly
decomposes and breaks down into H2O and CO2
Therefore, after the decomposition, the reaction would
look like this:
NaHCO3(aq) + CH3COOH(aq)  NaCH3COO(aq) + H2O(l) + CO2(g)
What actually happens?
The acetic acid reacts with the basic
sodium bicarbonate  carbonic acid
 Carbonic acid  carbon dioxide and water

 “eruption” (foaming, bubbling, fizzing, crackling)
from CO2 escaping the reacted solution

Only component left in the container:
 dilute solution of sodium acetate in water
○ NaCH3COO
Hypothesis After Calculations

10mL of acetic acid
 v = 0.010L
 c = 0.5M
 n = 0.005moles
NaHCO3(aq) + CH3COOH(aq)  NaCH3COO(aq) + H2O(l) + CO2(g)

Sodium bicarbonate
 n = 0.005moles (same number of moles as acetic acid)
 M = 23+1+12+(3)16 = 84g mol-1
 m = 0.42g
This should be the mass of sodium bicarbonate needed to react with
10mL of acetic acid to produce the greatest volume of carbon dioxide
Table 1: Volume of Carbon Dioxide Produced by the Different
Quantities of Baking Soda Reacted with 10mL of Vinegar
Mass of NaHCO3
Volume of CH3COOH
Volume of CO2
(g ± 0.001)
(mL ± 0.01)
(mL ± 0.1)
Trial 1
4.039
10.00
84.3
Trial 2
3.028
10.00
86.8
Trial 3
2.062
10.00
88.4
Trial 4
1.050
10.00
91.9
Trial 5
0.520
10.00
95.6
Trial 6
0.437
10.00
84.5
Trial 7
0.350
10.00
81.3
Table 2: Observations of Carbon Dioxide Produced by 10mL
of Vinegar Reacted with Different Quantities of Baking Soda
Mass of NaHCO3 (g)
Observations
4.039
One large gas bubble rises, followed by a train of gas bubbles rising
up steadily into the eudiometer tube, one after another
3.028
One large gas bubble rises, followed by a train of gas bubbles rising
up steadily into the eudiometer tube, one after another
2.062
One large gas bubble rises, followed by a train of gas bubbles rising
up steadily into the eudiometer tube, one after another
1.050
One large gas bubble rises, then more gas bubbles rise up steadily
but at a faster pace than the previous mass of baking soda (2g)
0.520
One large gas bubble rises, then more gas bubbles rise up even
faster than the previous mass of baking soda (1g)
0.437
One large gas bubble rises, followed by a train of gas bubbles rising
up steadily into the eudiometer tube, one after another, similar to the
trial with 4g of baking soda
0.350
On large gas bubble rises, followed by a train of gas bubbles rising
up steadily into the eudiometer tube, one after another, at a slower
pace than all previous trials
Graph 1: Volume of CO2 (mL) Produced by the Reaction
Between Baking Soda (NaHCO3) and Vinegar (CH3COOH)
Processing Data

n=m/M
 Calculations for moles of NaHCO3
○ Trial 1: 4.039/84 = 0.04808mol
○ Trial 2: 3.028/84 = 0.03605mol
○ Trial 3: 2.062/84 = 0.02455mol
○ Trial 4: 1.050/84 = 0.01250mol
○ Trial 5: 0.520/84 = 0.00619mol
○ Trial 6: 0.437/84 = 0.00520mol
○ Trial 7: 0.350/84 = 0.00417mol
 Calculations for moles of CH3COOH
○ All Trials: 10.00/60 = 0.1667mol
Graph 2: Comparing Ratios Between Different Moles
of Baking Soda Based on Its Mass to Moles of Vinegar
0.35
0.3
Moles
0.25
0.2
0.15
0.1
0.05
0
0.35
0.437
Baking Soda(mol)
0.52
1.05
2.062
Mass of Baking Soda(g)
Vinegar(mol)
Ratio of Baking Soda(mol) to Vinegar(mol)
3.028
4.039
Sample Calculations of Errors and Uncertainties for the
Reaction Between 0.520g of NaHCO3 and 10mL of CH3COOH

Percent Uncertainty
 (0.001/0.520)*100 = 19.23%
 (0.1/95.6)*100 = 10.46%
 19.23+10.46 = 29.69% ≈ 30%

Percent Error
 Experimental value
○ 95.6mL of CO2
 Theoretical value
○ 1mole = 24.5L
○ 0.00619mole = 0.152L
○ 0.152L = 152mL
○ ((152-95.6)/152)*100 = 37.11% ≈ 37%
Conclusion
Increasing trend line: suggests that masses of baking soda
below 0.5g increases rapidly in carbon dioxide production until it
reaches 0.5g
 Decreasing trend line: suggests that from the highest point of
carbon dioxide production (with 0.5g of baking soda) onwards,
the production of carbon dioxide from the reaction into the
eudiometer tube decreases steadily as the mass of baking soda
is increased
 Theoretical calculations under “Processing Data” indicate that
the results of the experiment support the calculated and
compared molar ratios of baking soda to vinegar, however, the
pattern in the production of carbon dioxide from the reaction
between baking soda and vinegar is flipped when graphed for
the ratios of different masses of baking soda to vinegar. This
signifies that the greater the molar ratio of baking soda to
vinegar, the lower the production of carbon dioxide during the
reaction between baking soda and vinegar will be

Evaluations





Accuracy and precision in measurements of baking soda and vinegar
 It was difficult to get the accurate mass of baking soda to 3 decimal places
through the electronic beam balance
 The vinegar was measured using a 25mL graduated cylinder, so the
volume of vinegar was estimated merely through judgment of the naked
eyes and is not very accurate nor precise
The surface area of baking soda was not controlled
There was a delay in the capturing of gas into the eudiometer tube
As the quantity of baking soda decreased, it got progressively trickier to
simultaneously mind the pouring of the entire quantity of baking soda into the
conical flask while minding the escape of gas released by the already started
reaction of baking soda to vinegar as the baking soda meets the vinegar
through contact little by little before the bung is attached to the flask, which
resulted in the spilling of baking soda
By the time the amount of baking soda progressively decreased to a mass
below 1.000g, perhaps due to the most reactive point of the reaction between
baking soda and vinegar being in the very beginning of the reaction, and with
the attachment of the bung to the conical flask being delayed, not all the gas
produced by the reaction went into the eudiometer tube (especially in the
beginning of the reaction), which may have produced inaccuracy in the
recorded volume of carbon dioxide released into the eudiometer tube
Evaluations




In order to keep the surface area of baking soda a control in the
experiment, use a spatula or a stirring rod to crush the baking
soda into powder completely, leaving absolutely no clumps left
In order to prevent from having too much gas escaping the
reaction before the conical flask is connected to the eudiometer
tube, have a partner ready to attach the bung into the opening of
the conical flask without delay after the respective mass of baking
soda is poured into the conical flask with 10mL of vinegar
In order to get a more accurate measurement to keep the volume
of vinegar a control in the experiment, use a pipette to measure
10mL of vinegar rather than a 25mL graduated cylinder
In order to get a more accurate measurement of baking soda
throughout the experiment, use a spatula to control the three
decimal places in the mass of baking soda being weighed on the
electronic beam balance by adding or taking out very small
amounts of baking soda from the container it is being weighed on
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<http://www.newton.dep.anl.gov/askasci/chem99/chem99096.ht
m>.
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